I think that some level of moderation is essential for any well run list.
And ensuring that posts to a list are relevant to a list's purpose is
critical. But how can this be achieved most effectively?

It seems to me that we can approach the issue from two quite distinct
perspectives:
- a boundaries approach
- a focus/repulsion approach

If we use the boundaries approach we have a strict application of rules
about what's in and what's not in. But in any complex issue there are
usually not sharp dividing lines between what's relevant and what's not.
Also using a strict boundaries approach dicussion can go on for ages
within the approved boundary but without really advancing the
purposes of the list, while another conversation that might be making a
contribution might be cut off at the socks because it triggers a boundary
rule.

Another way to go is to use a focus/repulsion approach. Someone
needs to define the core purpose of the list (the focus) and
topics/modes of dicussion that are generally considered to be not
relevent or appropriate and then contributions can be encouraged or
reined in depending on how well they contribute to the core purpose(s)
of the list or how bably they stray into repulsion topics/modes. If
contributions are straying too far off the focus of the list or too far
towards the repulsion topics/modes then the moderators can publicly or
privately caution contributors. When there is no sharp boundary there is
obviously room for interpretation about how off-topic a discussion is.
But at the end of the day the moderator has to make a final judgement.

My own feeling is that the SL4 list moderation process is too much
based on sharp boundaries and would benefit from using the
focus/repulsion approach.

An additional approach might be to ask discussants to take a topic off
the list and continue it privately (possibly via a temporary list) until the
thinking is developed far enough to bring the issue back to the SL4 list
in a way that is contributing strongly to the purpose of the list and that
avoids the repulsion modes.

Rather than either simply accepting or rejecting my suggestion, it might
be worth running an experiment for a short while using the
focus/repulsion approach to see how well it can work for the SL4 list
modertors and list participants.